Watercraft, including personal watercraft, are often powered by an internal combustion engine having an output shaft arranged to drive a water propulsion device. The engine which is used to power a personal watercraft often operates on a two-stroke operating cycle.
One problem associated with these engines is that when running at a low speed their exhaust content is fairly undesirable. For example, some unburned fuel may be contained in the exhaust which is directly exhausted into the atmosphere or water. In addition, the rate of fuel consumption of the engine at low speed is often high in relation to the required power output of the engine.
As one means to improve the exhaust content at low speed, the air/fuel ratio may be controlled by reducing the fuel delivery rate. In this manner, the fuel consumption rate is decreased and the exhaust content is improved.
This solution gives rise to its own problems, however. First, these two-cycle engines are known to run fairly rough at low speeds, including idle. A reduction in the fuel delivery rate may exacerbate this problem. In addition, if sudden acceleration of the engine is desired, the engine may stall.
An engine control for an engine of the type utilized to power a watercraft which is arranged to overcome the above-stated problems is desired.